I recently got a 7.62x39 upper for one of my Stags. I shot it for the first time today (very comfy & accurate) but I kept getting FTF's. It almost seemed like the bolt wasn't going back far enough to pick up the next round out of the mag. If I pulled the charging handle back each time it worked great. It didn't do this every time but quite a bit.

Question: Do I need a special buffer or buffer spring for this caliber? I'd like to find some better mags to. I have the plastic MWG ones . Does anyone know if I can modify a .223 AR mag to work with 7.62x39?

Other than that the upper is sweet! I was keeping them all in the 10 & X ring @ 100yds with a cheapie leaper 4x20 scope.